1. Technical Field
The invention is related to automated video recording and editing, and in particular, to a system and method for using a scriptable interface to control an abstraction of virtual cameramen in combination with physical cameras for predefining video editing rules to create automatically edited videos in real-time.
2. Related Art
Presentations such as speeches, lectures, seminars, classroom instruction, etc. are frequently recorded or captured using video recording equipment so that the presentation can be played back or viewed at some later time, or broadcast in real-time to a remote audience.
The simplest method for creating video recordings of such presentations is to have one or more human cameramen operating one or more cameras to record the various speakers and any slides or other visual aides used by the speaker during the presentation. Following the conclusion of the presentation, the recordings from the various cameras are then typically edited and combined to provide a final composite video which may then be made available for viewing. Alternately, the editing can also be done on the fly using a film crew consisting of one or more cameramen and a director, whose role is to choose the right camera and shot at any particular time.
Unfortunately, the use of human camera operators and manual editing of multiple recordings to create a composite video of various scenes of the presentation is typically a fairly expensive and/or time consuming undertaking. Consequently, several conventional schemes have attempted to automate both the recording and editing of presentations.
For example, one conventional scheme for providing automatic camera management and video creation generally works by manually positioning several hardware components, including cameras and microphones, in predefined positions within a lecture room. Views of the speaker or speakers and any PowerPoint™ type slides are then automatically tracked during the lecture. The various cameras will then automatically switch between the different views as the lecture progresses. Unfortunately, this system is based entirely in hardware, and tends to be both expensive to install and difficult to move to different locations once installed.
Another conventional scheme operates by automatically recording presentations with a small number of unmoving (and unmanned) cameras which are positioned prior to the start of the presentation. After the lecture is recorded, it is simply edited offline to create a composite video which includes any desired components of the presentation. One advantage to this scheme is that it provides a fairly portable system and can operate to successfully capture the entire presentation with a small number of cameras and microphones at relatively little cost. Unfortunately, the offline processing required to create the final video tends to very time consuming, and thus, more expensive. Further, because the final composite video is created offline after the presentation, this scheme is not typically useful for live broadcasts of the composite video of the presentation.
Another conventional scheme addresses some of the aforementioned problems by automating camera management in lecture settings. In particular, this scheme provides a set of videography rules to determine automated camera positioning, camera movement, and switching or transition between cameras. The videography rules used by this scheme depend on the type of presentation room and the number of audio-visual camera units used to capture the presentation. Once the equipment and videography rules are set up, this scheme is capable of operating to capture the presentation, and then to record an automatically edited version of the presentation. Real-time broadcasting of the captured presentation is also then available, if desired. Unfortunately, this scheme requires that the videography rules be custom tailored to each specific lecture room. Further, this scheme also requires the use of a number of analog video cameras, microphones and an analog audio-video mixer. This makes porting the system to other lecture rooms difficult and expensive, as it requires that the videography rules be rewritten and recompiled any time that the system is moved to a room having either a different size or a different number or type of cameras.
Therefore, what is needed is an automated video capture system and method that eliminates the need to provide human cameramen when recording a presentation. Further, such a system and method should provide for automatic real-time editing of the captured video, so as to allow for real-time broadcast of the edited presentation. Further, the system and method should be highly portable, such that it does not require complicated or time-consuming rewriting and recompiling of videography rules in the event that the meeting room or number or types of cameras are changed.